Though the leading character is older than the age group for which this story seems keyed, the mystery appeal is definitely to the early teens. The heroine, Victoria Tyrrell, disappointed that she cannot get a job as a newly graduated mining engineer, has mutinously come to a near - ghost town in the Colorado mountains with her invalid sister. The hills hold their mysteries: an unidentified woman has been found dead in an obscure shack on an abandoned mine; and Victoria sets to work to run down clues and do some prospecting on the side. There are some pleasantly spine chilling moments, but on the whole the plot is not as intricate as it seems at the start, and the conclusion is rather laboriously arrived at, though the locale is interesting, the characters credible enough, and the mining information sound. Slight love interest.